Releasing screw-arbor for milling-machines and the like.



N0. 842,787. PA'IBNIBD JAN. 29, 1907.

W. II.. HoLT. RELEASING SCREW ARBOR PoR MILLING MACHINES AND THE LIKE.

APPLICATION FILED JAN.30.1906.

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WILLIAM H. HOLT, OF PROVIDENCE, rRHODE ISLAND.

RELEASING SCREW-ARBOR FOR MILLING-MACHINES AND THE LIKE.

Specification of Letters Patent.

Patented Jan. 29. 1907.

Application filed January 30. 1906. Serial No. 298.667.

To L/,Z whom it 7mo/,y concern:

Be it known that I, WILLIAM H. HOLT, a citizen of the United States, residing at the city of Providence, in the county of Providence and State of Rhode Island, have invented a certain new and useful Improvement in Releasing Screw-Arbors for Milling- Machines and the Like, of which the following is a speciiication.

In the ordinary construction of a screwarbor for a milling-machine the cutter is screwed upon the threaded end portion of the arbor, and after the tool is in use the cutter becomes so firmly secured upon the arbor that it is very difficult to remove the cutter when necessary to have the same reground or otherwise, the common method being to strike against the face of one of the cutterteeth in order to unscrew both members apart, and which procedure frequently results in a broken cutter.

My invention consists of a milling-tool whose arbor has reduced concentric portions, so as to provide a shoulder therebetween and one of the reduced portionsv screw-threaded to engage thereby with the toothed cutter, and a sleeve loosely mounted upon the reduced portions of the arbor and having a shoulder to abut the shoulder of the latter so arranged that a partial turning of the sleeve causes the same to impinge against and hold the cutter firmly in position upon the arbor or to release from contact with the cutter in an expeditious manner.

In the accompanying sheet of drawings, Figure 1 represents a side elevation of a milling-arbor as embodying my improvement. Fig. 2 is a partial enlarged view, partly in section and partly in elevation, showing the relative position of my improved means for securing or releasing engagement with the cutter of the arbor. Fig. 3 is a cross-sectional view taken in line :c :c of Fig. 2. Fig. 4 is a side elevation of my improved sleeve member, and Fig. 5 represents the friction or holding end of the same.

Like reference characters indicate like parts.

A designates the tool as a whole, comprising the arbor a, my improved member b, and the common disk cutter c, respectively.

The arbor a has reduced concentric portions a and a2 in order to provide a shoulder between them, as at c3 in Fig. 2. The eXterior surface of the portion a2 of the arbor is partially screw-threaded to engage thereby in the threaded opening formed in the cutter c.

My improved member b is tubular in form and bored throughout its length, so as to fit loosely upon the reduced portions a and a2 of the arbor and having a shoulder b', Fig. 4, to abut the shoulder a3 of the same. One end of this tubular member b has a serrated surface b2, arranged to contact upon the rear face of the cutter c, and said sleeve is provided with two openings b3 b3, formed near its opposite end to receive a stem d, as indicated by broken lines in Fig. 3.

The threaded portion of the arbor is of a length to extend inwardly of the serrated end of the sleeve b, as shown in Fig. 2.

I show the arbor formed with a left-hand screw-thread and the teeth of the cutter as arranged for a right-hand boring or cutting.

In mounting the cutter upon the arbor it is first screwed up in the direction indicated by the arrow in Fig. 3 until it contacts with the adjacent serrated end of the sleeve, after which the stem or rod d (indicated by broken lines in said figure) is inserted in an opening b3 of said sleeve in order to turn the latter in the arrow direction, and thereby cause said sleeve to impinge against and hold the cutter in a powerful fixed position upon the arbor.

When it is desired to remove the cutter from the arbor, a slight pressure exerted upon the rod d in the reverse direction to that above described causes the sleeve to instantly release from frictional contact with the cutter, after which the latter may be readily unscrewed from its position upon the arbor.

It is apparent that my device affords a construction that is simple, cheap, and effective, and readily applied to arbors of millingmachines and the like.

What I claim, and desire to secure by Letters Patent, is-

The combination of a milling-tool whose arbor has reduced concentric portions forming a shoulder therebetween and the outer one of which portions is screw-threaded; a toothed cutter provided with a screw-thread- IOG ed opening to engage thereby the threaded In testimony whereof I affix my signature portlon of the arbor; a sleeve loosely mountn presence of tWo Witnesses.

ed upon the reduced portions of the arbor7 and having a shoulder to abut the shoulder of the f latter, and said sleeve provided With a serrated end adjacent the toothed cutter, substantially as set Jforth.V

WILLIAM H. HOLT.

Witnesses FRANK HOLLAND, GEO. W. CAMPBELL. 

